I am getting an soekris net5501-70 where I will install freebsd, and I will build my voip. I don't know how to build a voip because I never did one, and I am wondering which program should I use to set it up, I did a lot of googling and I found many programs, such as Asterisk or SER, but I still don't know the difference between either of them, and I am trying to understand how I am supposed to start to build it. I am still wondering which kind of phone I should use. For example, can I use a standard landline phone or do I have to use something else?